[Fix] Allow to have negative actions limits

lualib/rspamd_config_transform.lua

@@ -251,6 +251,24 @@ return function(cfg)
     logger.errx('no actions defined')
   end
 
+  -- Perform sanity check for actions
+  local actions_defs = {'greylist', 'add header', 'add_header',
+    'rewrite subject', 'rewrite_subject', 'reject'}
+
+  if not cfg.actions['no action'] and not cfg.actions['no_action'] and
+      not cfg.actions['accept'] then
+    for _,d in ipairs(actions_defs) do
+      if cfg.actions[d] then
+        if cfg.actions[d] < 0 then
+          cfg.actions['no action'] = cfg.actions[d] - 0.001
+          logger.infox('set no action score to: %s, as action %s has negative score',
+              cfg.actions['no action'], d)
+          break
+        end
+      end
+    end
+  end
+
   if not cfg.group then
     logger.errx('no symbol groups defined')
   else

src/libmime/filter.c

@@ -351,7 +351,7 @@ enum rspamd_action_type
 rspamd_check_action_metric (struct rspamd_task *task, struct rspamd_metric_result *mres)
 {
 	struct rspamd_action *action, *selected_action = NULL;
-	double max_score = 0, sc;
+	double max_score = -(G_MAXDOUBLE), sc;
 	int i;
 
 	if (task->pre_result.action == METRIC_ACTION_MAX) {